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A Complete Guide to Data Visualization in Python

A Complete Guide to Data Visualization in Python
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In this blog, we’ll explore the basics of data visualization in Python, its benefits, and how it can help you make better decisions based on data-driven insights. So, buckle up and get ready to unleash the power of Python for data visualization!

Table of Contents

Watch this Data Visualization video to learn more about its concepts:

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What is Data Visualization in Python?

Data visualization in Python is an essential part of data analysis since it helps display complex data clearly and clearly. Python is a popular programming language with many data visualization packages to construct visually attractive data visualizations.

  • Data Representation: Data visualization in Python means visually presenting data and information, aiding data analysts, scientists, and decision-makers in understanding complex data and detecting patterns.
  • Python’s Strength: Python is a robust language widely used in data analysis. It offers a variety of data visualization libraries, including Matplotlib, Seaborn, Plotly, and Bokeh, to create high-quality data visualizations.
  • Visual Elements: Python libraries provide numerous types of plots and charts, such as line plots, scatter plots, bar plots, histograms, and heat maps.
  • Data Insight: Python data visualization allows for pattern and trend recognition, simplifying data communication to non-technical audiences and supporting data-driven decision-making.
  • Python’s Appeal: Python’s popularity for data visualization is due to its user-friendliness, flexibility, compatibility with various data formats, and open-source nature, allowing user contributions to enhance data visualization tools.

Python Data Visualization Libraries

Python is well known for its applications in data analysis and visualization. Here are some data visualization libraries in python you can use to gain insights for given data. 

LibraryDescriptionInstallation Command
MatplotlibA versatile Python library for creating static, animated, and interactive visualizations.pip install matplotlib
Pandas VisualizationBuilt on Matplotlib, it offers a high-level interface for creating visualizations from Pandas DataFrames.pip install pandas-visualization
SeabornA Python visualization library built on Matplotlib, known for creating attractive statistical graphics.pip install seaborn
PlotnineBased on the grammar of graphics, it provides a concise and easy-to-read syntax for creating complex visualizations.pip install plotnine
PlotlyEnables interactive visualizations that can be embedded in web pages or shared on social media.pip install plotly

Data Science IITM Pravartak

Data Visualization in Python using Matplotlib

Matplotlib is a popular data visualization package in Python that allows you to generate a wide range of charts and plots. Here are the fundamental steps for creating a simple visualization with Matplotlib.

1. Import the necessary libraries and modules:

import matplotlib.pyplot as plt
import numpy as np

2. Create some data to plot:

x = np.linspace(0, 10, 100)
y = np.sin(x)

3. Create a figure and an axis object:

fig, ax = plt.subplots()

4. Plot the data:

ax.plot(x, y)

5. Customize the plot with titles, labels, and other features:

ax.set_title("Sine Wave")
ax.set_xlabel("X")
ax.set_ylabel("Y")

6. Show the plot:

plt.show()

This code facilitates the generation of a straightforward sine wave plot. Moreover, it provides options for modifying plot colors, fonts, and styles. Due to the comprehensive documentation and strong community backing of Matplotlib, one can find numerous online examples and tools that aid in the creation of desired visualizations.

How to Visualize Data in Python

How to Visualize Data in Python

Python has many tools and packages for data visualization. Following are some general procedures to take while visualizing data in Python:

  • Import the necessary libraries
  • Load the data
  • Choose the appropriate plot type for the data
  • Customize the plot with labels, titles, and other features
  • Show the plot

Selecting the right plot type for the data you’re displaying is critical. Line plots, for example, are suitable for displaying trends across time, whereas scatter plots help show connections between variables.

Visualization of CSV Data by Python

To visualize CSV data, you can utilize popular Python data visualization libraries such as Matplotlib or Seaborn. Here’s a general outline of the steps involved:

  • Import the Required Libraries:
    Import the necessary libraries for data manipulation and visualization. For this example, we’ll use pandas for data manipulation and Matplotlib for visualization.
import pandas as pd
import matplotlib.pyplot as plt
  • Read the CSV Data:
    Use pandas to read the CSV file and store it in a DataFrame.
df = pd.read_csv('your_file.csv')
  • Explore the Data:
    Before visualizing the data, it’s helpful to understand its structure. You can check the columns, data types, and basic statistics of the DataFrame.
# View the first few rows of the DataFrame
print(df.head())
# Get basic statistics of the data
print(df.describe())
# Check the column names
print(df.columns)
  • Plot the Data:
    Use Matplotlib or other data visualization libraries to create visual representations of your data. The specific type of plot will depend on the nature of your data and the insights you want to convey.
    This is a basic example, but you can explore various plot types such as bar plots, scatter plots, histograms, or box plots, depending on your data and visualization goals. Matplotlib offers a wide range of customization options to tailor the plots to your specific needs.
# Example: Create a line plot of a numeric column
plt.plot(df['column_name'])
plt.title('Line Plot')
plt.xlabel('X-axis label')
plt.ylabel('Y-axis label')
plt.show()
  • Save or Show the Plot:
    Depending on your requirements, you can save the plot to a file or display it directly in the Python environment.
# Save the plot as an image file
plt.savefig('plot.png')
# Display the plot
plt.show()

Remember to customize the plot according to your specific data and visualization requirements. 

Data Science SSBM

Visualization of TSV Data by Python

Below is an example of Python data visualization of TSV data in the form of Line Graph:

We took a dataset of Open food facts from Kaggle. Open Food Facts is a free, open, collaborative database of food products from around the world, with ingredients, allergens, nutrition facts, and other information 

You can download the dataset from Kaggle and import it to Google Colab using the following steps:

  • Go to your Google Drive and create a folder named openfoodfacts to mount the dataset.
  • Upload the en.openfoodfacts.org.products.tsv file to that folder. This file contains the data for over a million products in tab-separated format.
  • Open a new notebook in Google Colab and mount your Google Drive by running this code:
from google.colab import drive
drive.mount('/drive')
  • You will be asked to enter an authorization code. Follow the link provided and copy the code. Paste it in the box and press enter.
  • Now you can access your Google Drive files from Colab. To read the Open Food Facts data, you can use the pandas library. Run this code:
import pandas as pd
import matplotlib.pyplot as plt
data = pd.read_tsv('/drive/MyDrive/openfoodfacts/en.openfoodfacts.org.products.tsv', sep='\t')
data.head() show you the first five rows of the data. You can explore the data further using pandas methods and attributes, such as data.shape, data.columns, data.describe(), etc.
  • To visualize the data, you can use libraries such as matplotlib, seaborn, plotly, etc. 

For example, to plot the line graph of nutrition values of the products, you can run this code:

import plotly.express as px
import numpy as np

data_sorted = data.sort_values(by='nutrition-score-fr_100g')

bins = np.linspace(data_sorted['nutrition-score-fr_100g'].min(), data_sorted['nutrition-score-fr_100g'].max(), 51)

data_grouped = data_sorted.groupby(pd.cut(data_sorted['nutrition-score-fr_100g'], bins)).size()

plt.plot((bins[:-1] + bins[1:]) / 2, data_grouped)
plt.xlabel('Nutri-Score (kcal/100g)')
plt.ylabel('Frequency')
plt.title('Line graph of Nutrition values')
plt.show()
Line graph of Nutrition Values

Data Visualization Projects in Python

Here are some examples of data visualization projects that with Python:

  • Visualizing the distribution of a dataset using a histogram
  • Creating a line plot to show trends over time
  • Creating a scatter plot to show the relationship between two variables
  • Creating a heatmap to show the correlation between variables
  • Creating a bar chart to compare the values of different categories

Best Practices for Data Visualization in Python

Creating compelling data visualizations in Python requires more than selecting a library and creating a plot. Some best practices can ensure that the visualizations are clear, informative, and accurate. Here are some key points to consider when creating data visualizations in Python:

  • Choose the Right Visualization Type: Select the most appropriate visualization type based on the data you want to represent. Different data structures are best suited for specific plots and charts. For example, use line plots for showing trends over time and scatter plots to reveal relationships between variables.
  • Simplify Your Visualizations: Keep your visualizations simple and easy to read. Avoid cluttering the plot with unnecessary elements like grid lines, tick marks, and legends. Use colors and labels sparingly and only when essential to prevent overwhelming the viewer.
  • Use Appropriate Scales: Employ scales that fit the data. For instance, use logarithmic scales for data spanning multiple orders of magnitude, and linear scales for data with a smaller range of variation.
  • Label Axes and Add a Title: Ensure your plot is well-labeled. Label the axes and provide a clear title for the plot. This adds context and makes it easier for the viewer to understand.
  • Provide Data Context: Offer context for the data, including details about the data source, the collection timeframe, and relevant units of measurement. This context helps the viewer grasp what the data represents.
  • Test with Different Audiences: Test your visualization with various audiences to ensure it effectively communicates the intended message. This process can reveal misunderstandings and areas for improvement, enhancing the clarity and impact of your visualization.

Conclusion

In conclusion, Python allows data scientists and analysts with a powerful set of tools and packages for creating stunning and informative Python data visualizations. From basic charts to interactive plots, Python’s versatile libraries enable users to transform raw data into appealing visual. By following best practices in data visualization, professionals can unlock the true potential of their data and effectively communicate to audiences. With Python’s rich ecosystem of visualization options and a commitment to best practices, the world of data becomes more accessible and impactful. So, let us accept the power of Python and develop the art of storytelling through compelling visualizations, bridging the gap between data and understanding.

About the Author

Principal Data Scientist

Meet Akash, a Principal Data Scientist with expertise in advanced analytics, machine learning, and AI-driven solutions. With a master’s degree from IIT Kanpur, Aakash combines technical knowledge with industry insights to deliver impactful, scalable models for complex business challenges.